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HP OpenVMS System Services Reference Manual
Note that two processes on different nodes cannot use the termination
mailbox for general interprocess communication.
The accounting message is sent before process rundown is initiated but
after the process name has been set to null. Thus, a significant
interval of time can occur between the sending of the accounting
message and the final deletion of the process.
To receive the accounting message, the caller must issue a read to the
mailbox. When the I/O completes, the second longword of the I/O status
block, if one is specified, contains the process identification of the
deleted process.
The $ACCDEF macro defines symbolic names for offsets of fields within
the accounting message. The offsets, their symbolic names, and the
contents of each field are shown in the following table. Unless stated
otherwise, the length of the field is 4 bytes.
| Offset |
Symbolic Name |
Contents |
|
0
|
ACC$W_MSGTYP
|
MSG$_DELPROC (2 bytes)
|
|
2
|
|
Not used (2 bytes)
|
|
4
|
ACC$L_FINALSTS
|
Exit status code
|
|
8
|
ACC$L_PID
|
External process identification
|
|
12
|
|
Not used (4 bytes)
|
|
16
|
ACC$Q_TERMTIME
|
Current time in system format at process termination (8 bytes)
|
|
24
|
ACC$T_ACCOUNT
|
Account name for process, blank filled (8 bytes)
|
|
32
|
ACC$T_USERNAME
|
User name, blank filled (12 bytes)
|
|
44
|
ACC$L_CPUTIM
|
CPU time used by the process, in 10-millisecond units
|
|
48
|
ACC$L_PAGEFLTS
|
Number of page faults incurred by the process
|
|
52
|
ACC$L_PGFLPEAK
|
Peak paging file usage
|
|
56
|
ACC$L_WSPEAK
|
Peak working set size
|
|
60
|
ACC$L_BIOCNT
|
Count of buffered I/O operations performed by the process
|
|
64
|
ACC$L_DIOCNT
|
Count of direct I/O operations performed by the process
|
|
68
|
ACC$L_VOLUMES
|
Count of volumes mounted by the process
|
|
72
|
ACC$Q_LOGIN
|
Time, in system format, that process logged in (8 bytes)
|
|
80
|
ACC$L_OWNER
|
Process identification of owner
|
The length of the termination message is equated to the constant
ACC$K_TERMLEN.
stsflg
| OpenVMS usage: |
mask_longword |
| type: |
longword (unsigned) |
| access: |
read only |
| mechanism: |
by value |
Options selected for the created process. The stsflg
argument is a longword bit vector wherein a bit corresponds to an
option. Only bits 0 to 22 are used; the others are reserved and must be
0.
Each option (bit) has a symbolic name, which the $PRCDEF macro defines.
You construct the stsflg argument by performing a
logical OR operation using the symbolic names of each desired option.
The following table describes the symbolic name of each option:
| Symbolic Name |
Description |
|
PRC$M_BATCH
|
Create a batch process. IMPERSONATE privilege is required.
|
|
PRC$M_IMPERSONATE
|
Create a detached process under another UIC.
|
|
PRC$M_DISAWS
|
Disable system-initiated working set adjustment.
|
|
PRC$M_HIBER
|
Force process to hibernate before it executes the image.
|
|
PRC$M_HOME_RAD
|
Assign process to specified home resource affinity domain (RAD).
RAD is supported on AlphaServer GS series systems and starting from OpenVMS Version 8.4, support is extended to NUMA capable Integrity servers.
|
|
PRC$M_IMGDMP
|
Enable image dump facility. If an image terminates due to an unhandled
condition, the image dump facility writes the contents of the address
space to a file in your current default directory. The file name is the
same as the name of the terminated image. The file type is .DMP.
|
|
PRC$M_INTER
|
Create an interactive process. This option is meaningful only if the
image argument specifies SYS$SYSTEM:LOGINOUT.EXE. The
purpose of this option is to provide you with information about the
process. When you specify this option, it identifies the process as one
that is in communication with another user (an interactive process).
For example, if you use the DCL lexical function F$MODE to make an
inquiry about a process that has specified the PRC$M_INTER option,
F$MODE returns the value INTERACTIVE.
|
|
PRC$M_KT_LIMIT
|
Assign the specified kernel thread limit to the created process.
|
|
PRC$M_NETWRK
|
Create a process that is a network connect object. IMPERSONATE
privilege required.
|
|
PRC$M_NOACNT
|
Do not perform accounting. ACNT privilege is required.
|
|
PRC$M_NOPASSWORD
|
Do not display the
Username: and
Password: prompts if the process is interactive and detached
and the image is SYS$SYSTEM:LOGINOUT.EXE. If you specify this option in
your call to $CREPRC, the process created by the call is logged in
under the user name associated with the creating process. If you do not
specify this option for an interactive process, SYS$SYSTEM:LOGINOUT.EXE
prompts you for the user name and password to be associated with the
process. The prompts are displayed at the SYS$INPUT device.
|
|
PRC$M_NOUAF
|
Do not check authorization file if the process is detached and the
image is SYS$SYSTEM:LOGINOUT.EXE. You should not specify this option if
a subprocess is being created.
In previous versions of the operating system, the symbolic name of
this option was PRC$M_LOGIN. The symbolic name has been changed to more
accurately denote the effect of setting this bit. For compatibility
with existing user programs, you can still specify this bit as
PRC$M_LOGIN.
This flag prevents the loading of the new process's security
profile from the contents of the UAF record associated with the
specified user name. Restrictions are still enforced on the UAF record,
if it exists, for account disuser, account expiration, and
primary/secondary days/hours.
|
|
PRC$M_PARSE_EXTENDED
|
Sets the PARSE_STYLE_PERM and the PARSE_STYLE_IMAGE properties for the
new process to EXTENDED.
|
|
PRC$M_PSWAPM
|
Inhibit process swapping. PSWAPM privilege is required.
|
|
PRC$M_SSFEXCU
|
Enable system service failure exception mode.
|
|
PRC$M_SSRWAIT
|
Disable resource wait mode.
|
|
PRC$M_SUBSYSTEM
|
Inherit any protected subsystem identifiers. The default is that the
new process does not inherit subsystem identifiers.
|
|
PRC$M_TCB
|
Mark a process as part of the trusted computing base (TCB). As such, it
is expected to perform its own auditing. IMPERSONATE privilege is
required.
|
Note that options PRC$M_BATCH, PRC$M_INTER, PRC$M_NOUAF, PRC$M_NETWRK,
and PRC$M_NOPASSWORD are intended for use by HP software.
itmlst
| OpenVMS usage: |
reserved |
| type: |
longword (unsigned) |
| access: |
|
The itmlst argument is reserved by HP.
node
| OpenVMS usage: |
SCS_nodename |
| type: |
character-coded text string |
| access: |
read only |
| mechanism: |
by descriptor--fixed-length string descriptor |
Name of the OpenVMS Cluster node on which the process is to be created.
The node argument is the address of a character string
descriptor pointing to a 1- to 6-character SCS node name string. If the
argument is present but zero or if the string is zero length, the
process is created on the current node.
home_rad
| OpenVMS usage: |
longword_unsigned |
| type: |
longword (unsigned) |
| access: |
read only |
| mechanism: |
by value |
Sets the home resource affinity domain (RAD) of a process.
The home RAD is determined by the operating system, unless you
explicitly request one. If bit PRC$M_HOME_RAD in the
stsflg is set, home_rad is the RAD on
which the process is to start. Note that you may set this bit to 0 on
non-RAD systems.
RAD is supported on AlphaServer GS series systems and starting from OpenVMS Version 8.4, support is extended to NUMA capable Integrity servers. For more information about using RADs, see the HP
OpenVMS Alpha Partitioning and Galaxy Guide.
kt_limit
| OpenVMS usage: |
longword_signed |
| type: |
longword (signed) |
| access: |
read only |
| mechanism: |
by value |
Sets the limit of the number of kernel threads that can be created in
the process. If the value is greater than the SYSGEN MULTITHREAD
parameter, an error message is returned.
The number of kernel threads that can be created in a process, is by
default controlled by the MULTITHREAD SYSGEN parameter. The
kt_limit argument is used to further limit the number
of possible kernel threads for the process.
Description
The Create Process service creates a subprocess or detached process on
behalf of the calling process. A subprocess can be created only on the
current OpenVMS Cluster node. A detached process can be created on the
current OpenVMS Cluster node or on the node specified with the
node argument.
A detached process is a fully independent process. For example, the
process that the system creates when you log in is a detached process.
A subprocess, on the other hand, is related to its creating process in
a treelike structure; it receives a portion of the creating process's
resource quotas and must terminate before the creating process. Any
subprocesses that still exist when their creator is being deleted are
automatically deleted.
The presence of the uic argument,
node argument, or the PRC$M_IMPERSONATE flag specifies
that the created process is detached.
Creating a process is synchronous in that the process has actually been
created and its PID determined before control returns to the program
that requested the system service. Note, however, that the new process
has not necessarily begun to execute at that point. Some error
conditions are not detected until the created process executes. These
conditions include an invalid or nonexistent image; invalid SYS$INPUT,
SYS$OUTPUT, or SYS$ERROR logical name equivalence; inadequate quotas;
or insufficient privilege to execute the requested image.
In creating a detached or subprocess, you can specify that the process
run the image SYS$SYSTEM:LOGINOUT.EXE. During interactive logins,
LOGINOUT performs the following functions:
- It validates user name and password.
- It reads the system authorization file record associated with that
user and redefines the process environment based on information from
the record.
- It maps a command language interpreter (CLI) into the process and
passes control to it.
The CLI reads a command from SYS$INPUT, processes it, and reads another
command. The presence of the CLI enables the process to execute
multiple images. It also enables an image running in the process to use
Run-Time Library procedures, such as LIB$SPAWN, LIB$DO_COMMAND, and
LIB$SET_LOGICAL, that require a CLI.
Running in the context of a process you create through $CREPRC,
LOGINOUT can perform some or all of the preceding steps, depending on
whether the process is a subprocess or a detached process and on the
values of PRC$M_NOPASSWORD and PRC$M_NOUAF in the
stsflg argument.
Certain characteristics of a created process can be specified
explicitly through $CREPRC system service arguments, while other
characteristics are propagated implicitly from the $CREPRC caller.
Implicit characteristics include the following:
- Current default directory
- Creator's equivalence name for SYS$DISK
- User and account names
- Command language interpreter (CLI) name and command table file name
Note, however, that after the process has been created, if it runs
LOGINOUT and LOGINOUT redefines the process environment, those
characteristics will be overridden by information from the system
authorization file.
Several process characteristics are relevant to the creation of a
process on another OpenVMS Cluster node, in particular, process quotas,
default directory, SYS$DISK equivalence name, CLI name, and CLI command
table name.
Quotas for a process created on another OpenVMS Cluster node are
calculated as previously described in the section on the use of the
quota list; namely, they are based on explicit values passed by the
creator and system parameters on the other OpenVMS Cluster node. If the
other node has its own authorization file with node-specific quotas,
you might want to specify in the $CREPRC request that the process run
LOGINOUT so it can redefine the process environment based on that
node's quotas for the user.
Unless overridden by LOGINOUT, the new process will use its creator's
default disk and directory. If the disk is not mounted clusterwide, the
created process might need to redefine SYS$DISK with an equivalence
name that specifies a disk accessible from that node.
When you set the PRC$M_NOUAF flag in the stsflg
argument and create a process running LOGINOUT, LOGINOUT will attempt
to map a CLI and command table with the same file names as those
running in your process. The CLI and command table images must
therefore have already been installed by the system manager on the
other node. Problems can arise when you are using something other than
the DCL CLI and its standard command tables. For example, if you are
running on a VAX node with MCR as your current CLI, LOGINOUT will be
unable to map that CLI on an Alpha or Integrity servers node. The new
process will be created but then aborted by LOGINOUT.
A detached process is considered an interactive process only if (1) the
process is created with the PRC$M_INTER option specified and (2)
SYS$INPUT is not defined as a file-oriented device.
The $CREPRC service requires system dynamic memory.
Required Access or Privileges
The calling process must have the following:
- IMPERSONATE or CMKRNL privilege to create any of the following
types of process:
- A detached process with a UIC that is different from the UIC of the
calling process
- A detached process with a larger value specified for some quota
than is authorized for the caller
- A detached process on another node if the system parameter
CWCREPRC_ENABLE has a value of 0
- IMPERSONATE privilege to create any of the following types of
process:
- A batch process
- A network process
- A trusted computing base process
- ALTPRI privilege to create a subprocess with a higher base priority
than the calling process
- SETPRV privilege to create a process with privileges that the
calling process does not have
- PSWAPM privilege to create a process with process swap mode disabled
- ACNT privilege to create a process with accounting functions
disabled
- OPER privilege to create a detached process on another OpenVMS
Cluster node on which interactive logins have not yet been enabled
Required Quota
The number of subprocesses that a process can create is controlled by
the subprocess (PRCLM) quota; this quota is returned when a subprocess
is deleted.
The number of detached processes on any one OpenVMS Cluster node that a
process can create with the same user name is controlled by the
MAXDETACH entry in the user authorization file (UAF).
When a subprocess is created, the value of any deductible quota is
subtracted from the total value the creating process has available, and
when the subprocess is deleted, the unused portion of any deductible
quota is added back to the total available to the creating process. Any
pooled quota value is shared by the creating process and all its
subprocesses.
Related Services
$CANEXH, $DCLEXH, $DELPRC, $EXIT, $FORCEX, $GETJPI, $GETJPIW, $HIBER,
$PROCESS_SCAN, $RESUME, $SETPRI, $SETPRN, $SETPRV, $SETRWM, $SUSPND,
$WAKE
Condition Values Returned
|
SS$_ACCVIO
|
The caller cannot read a specified input string or string descriptor,
the privilege list, or the quota list; or the caller cannot write the
process identification.
|
|
SS$_BADRAD
|
The specified RAD contains no memory or contains no active CPUs, or the
specified RAD is greater than or equal to the maximum number of RADs on
the system. Use the $GETSYI item code RAD_MAX_RADS to determine the
maximum number of RADs on the system.
|
|
SS$_DUPLNAM
|
The specified process name duplicates one already specified within that
group.
|
|
SS$_EXPRCLM
|
The creation of a detached process failed because the creating process
already reached its limit for the creation of detached processes. This
limit is established by the MAXDETACH quota in the user authorization
file (UAF) of the creating process.
|
|
SS$_EXQUOTA
|
At least one of the following conditions is true:
- The process has exceeded its quota for the creation of subprocesses.
- A quota value specified for the creation of a subprocess exceeds
the creating process's corresponding quota.
- The quota is deductible and the remaining quota for the creating
process would be less than the minimum.
|
|
SS$_INCOMPAT
|
The remote node is running an incompatible version of the operating
system, namely, one that does not support remote process creation.
|
|
SS$_INSFMEM
|
The system dynamic memory is insufficient for the requested operation.
|
|
SS$_INVARG
|
An invalid argument is specified.
|
|
SS$_INVKTLIM
|
A value lower than 0, or a value higher than the SYSGEN parameter
MULTITHREAD is specified.
|
|
SS$_IVLOGNAM
|
At least one of the following two conditions is true:
- The specified process name has a length of 0 or has more than 15
characters.
- The specified image name, input name, output name, or error name
has more than 255 characters.
|
|
SS$_IVQUOTAL
|
The quota list is not in the proper format.
|
|
SS$_IVSTSFLG
|
A reserved status flag was specified.
|
|
SS$_NODELEAVE
|
The specified node was removed from the OpenVMS Cluster during the
$CREPRC service's execution.
|
|
SS$_NOPRIV
|
The caller violated one of the privilege restrictions.
|
|
SS$_NORMAL
|
The service completed successfully.
|
|
SS$_NOSLOT
|
No process control block is available; in other words, the maximum
number of processes that can exist concurrently in the system has been
reached.
|
|
SS$_NOSUCHNODE
|
The specified node is not currently a member of the cluster.
|
|
SS$_REMRSRC
|
The remote node has insufficient resources to respond to the request.
(Bring this error to the attention of your system manager.)
|
|
SS$_UNREACHABLE
|
The remote node is a member of the cluster but is not accepting
requests. This is normal for a brief period early in the system boot
process.
|
$CRETVA
Adds a range of demand-zero allocation pagelets to a process's virtual
address space for the execution of the current image.
Format
SYS$CRETVA inadr ,[retadr] ,[acmode]
C Prototype
int sys$cretva (struct _va_range *inadr, struct _va_range *retadr,
unsigned int acmode);
Arguments
inadr
| OpenVMS usage: |
address_range |
| type: |
longword (unsigned) |
| access: |
read only |
| mechanism: |
by reference |
Address of a 2-longword array containing the starting and ending
virtual addresses of the pages to be created. If the starting and
ending virtual addresses are the same, a single page is created. The
addresses are adjusted up or down to fall on CPU-specific page
boundaries. Only the virtual page number portion of the virtual address
is used; the low order byte-within-page bits are ignored.
retadr
| OpenVMS usage: |
address_range |
| type: |
longword (unsigned) |
| access: |
write only |
| mechanism: |
by reference--array reference or descriptor |
Address of a 2-longword array to receive the starting and ending
virtual addresses of the pages created.
On Alpha and Integrity server systems, the retadr
argument should be checked by programs for actual allocation. Because
the Alpha and Integrity servers architectures define more than one page
size, more space might be created than was specified in the
inadr argument.
acmode
| OpenVMS usage: |
access_mode |
| type: |
longword (unsigned) |
| access: |
read only |
| mechanism: |
by value |
Access mode and protection for the new pages. The
acmode argument is a longword containing the access
mode.
The $PSLDEF macro defines the following symbols for the four access
modes:
| Symbol |
Access Mode |
|
PSL$C_KERNEL
|
Kernel
|
|
PSL$C_EXEC
|
Executive
|
|
PSL$C_SUPER
|
Supervisor
|
|
PSL$C_USER
|
User
|
The most privileged access mode used is the access mode of the caller.
The protection of the pages is read/write for the resultant access mode
and those more privileged.
Description
The Create Virtual Address Space service adds a range of demand-zero
allocation pages to a process's virtual address space for the execution
of the current image.
Pages are created starting at the address contained in the first
longword of the location addressed by the inadr
argument and ending with the second longword. The ending address can be
lower than the starting address. The retadr argument
indicates the byte addresses of the pages created.
If an error occurs while pages are being created, the
retadr argument, if specified, indicates the pages
that were successfully created before the error occurred. If no pages
were created, both longwords of the retadr argument
contain the value --1.
If $CRETVA creates pages that already exist, the service deletes those
pages if they are not owned by a more privileged access mode than that
of the caller. Any such deleted pages are reinitialized as demand-zero
pages. For this reason, it is important to use the
retadr argument to capture the address range actually
created. Because the Alpha and Integrity servers architectures have a
larger page size than the VAX architecture, more space is potentially
affected on Alpha and Integrity server systems.
Required Access or Privileges
None
Required Quota
The paging file quota (PGFLQUOTA) of the process must be sufficient to
accommodate the increased size of the virtual address space.
Related Services
$ADJSTK, $ADJWSL, $CRMPSC, $DELTVA, $DGBLSC, $EXPREG, $LCKPAG, $LKWSET,
$MGBLSC, $PURGWS, $SETPRT, $SETSTK, $SETSWM, $ULKPAG, $ULWSET, $UPDSEC,
$UPDSECW
The Expand Program/Control Region ($EXPREG) service also adds pages to
a process's virtual address space.
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